fix(HAI-092): use generateWorktreeName for fresh worktree directories

- Replace task ID with generateWorktreeName for worktree directory paths
- Worktrees now use human-friendly adjective-noun names (e.g. swift-falcon)
- Add tests for fresh worktree naming, task ID exclusion, and resumed task reuse

packages/engine/src/executor.test.ts

@@ -32,6 +32,7 @@ import { createHaiAgent } from "./pi.js";
 import { execSync } from "node:child_process";
 import { findWorktreeUser, aiMergeTask } from "./merger.js";
 import { WorktreePool } from "./worktree-pool.js";
+import { generateWorktreeName } from "./worktree-names.js";
 import type { Column, Task, TaskDetail } from "@hai/core";
 
 const mockedCreateHaiAgent = vi.mocked(createHaiAgent);
@@ -349,6 +350,78 @@ describe("TaskExecutor worktreeInitCommand", () => {
   });
 });
 
+describe("TaskExecutor worktree naming", () => {
+  const makeTask = (id = "HAI-030", worktree?: string) => ({
+    id,
+    title: "Test",
+    description: "Test",
+    column: "in-progress" as const,
+    dependencies: [],
+    steps: [],
+    currentStep: 0,
+    log: [],
+    createdAt: new Date().toISOString(),
+    updatedAt: new Date().toISOString(),
+    ...(worktree ? { worktree } : {}),
+  });
+
+  const mockedGenerateWorktreeName = vi.mocked(generateWorktreeName);
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+    mockedExistsSync.mockReturnValue(false);
+    mockedGenerateWorktreeName.mockReturnValue("swift-falcon");
+    mockedCreateHaiAgent.mockResolvedValue({
+      session: {
+        prompt: vi.fn().mockResolvedValue(undefined),
+        dispose: vi.fn(),
+      },
+    } as any);
+  });
+
+  it("uses generateWorktreeName for fresh worktree directories", async () => {
+    const store = createMockStore();
+    const executor = new TaskExecutor(store, "/tmp/test");
+
+    await executor.execute(makeTask());
+
+    // The worktree path stored should use the generated name, not the task ID
+    expect(store.updateTask).toHaveBeenCalledWith("HAI-030", {
+      worktree: "/tmp/test/.worktrees/swift-falcon",
+    });
+    expect(mockedGenerateWorktreeName).toHaveBeenCalledWith("/tmp/test");
+  });
+
+  it("does NOT use task ID as worktree directory name for fresh worktrees", async () => {
+    const store = createMockStore();
+    const executor = new TaskExecutor(store, "/tmp/test");
+
+    await executor.execute(makeTask("HAI-099"));
+
+    // Verify the worktree path does NOT contain the task ID
+    const updateCalls = store.updateTask.mock.calls;
+    const worktreeUpdate = updateCalls.find(
+      (call: any[]) => call[1]?.worktree !== undefined,
+    );
+    expect(worktreeUpdate).toBeDefined();
+    expect(worktreeUpdate![1].worktree).not.toContain("HAI-099");
+    expect(worktreeUpdate![1].worktree).toContain("swift-falcon");
+  });
+
+  it("reuses stored worktree path for resumed tasks", async () => {
+    const existingPath = "/tmp/test/.worktrees/calm-river";
+    mockedExistsSync.mockReturnValue(true);
+
+    const store = createMockStore();
+    const executor = new TaskExecutor(store, "/tmp/test");
+
+    await executor.execute(makeTask("HAI-031", existingPath));
+
+    // Should NOT generate a new name — reuse the stored path
+    expect(mockedGenerateWorktreeName).not.toHaveBeenCalled();
+  });
+});
+
 describe("TaskExecutor worktree pool integration", () => {
   const makeTask = (id = "HAI-020") => ({
     id,

packages/engine/src/executor.ts

@@ -271,7 +271,9 @@ export class TaskExecutor {
 
       // Create or reuse worktree — try pool first when recycling is enabled
       const branchName = `hai/${task.id.toLowerCase()}`;
-      let worktreePath = task.worktree || join(this.rootDir, ".worktrees", task.id);
+      // Use generateWorktreeName for human-friendly directory names (adjective-noun pattern)
+      // instead of task.id, so worktrees are named like ".worktrees/swift-falcon"
+      let worktreePath = task.worktree || join(this.rootDir, ".worktrees", generateWorktreeName(this.rootDir));
       let isResume = existsSync(worktreePath);
       let acquiredFromPool = false;
       const settings = await this.store.getSettings();